During the coming year, we will do the following: 1. Continue studying the adsorption of polymers on COM, with emphasis on theoretical analysis of RNA, and data generation for polyglutamic acid and pentosan sulfate (zeta potential, particle size distribution, solution depletion and inhibition of growth and nucleation). 2. Proposed with the development of a multiwell nucleator to address the stochastic character of nucleation. 3. Do an electron microscopic study of the morphology of nascent COM precipitates. 4. Continue studies of the encrustability of chemically modified urinary catheter surfaces. 5. Continue studies of the physical aspects of extracorporeal shock wave lithotripsy. 6. Continue to study lamination structure during calcium oxalate stone growth induced on plastic foreign bodies. Alterations in urine pH and gender will be studied to determine their influence upon stone structure. 7. Determine the effect of sub-lethal cell injury upon heterogenous calcium oxalate crystal formation in the urine.